This invention relates generally to a conveyor belt scraper.
It is known to make use of a conveyor scraper wherein the scraping element, or each scraping element when there are a plurality of such elements, is flexible or is mounted to a spring of suitable form which allows to-and-fro movement of the scraping element, during use.
With the aforementioned type of scraper cleaning of a conveyor belt is achieved by adjusting each scraping element towards the belt surface and applying pressure so that the flexible scraping element, or the spring, as the case may be, is tensioned to remove slack and creep and to provide the necessary resistance to the moving belt so that material adhering to the belt is removed.
The pressure which is applied to flex the scraping element or tension the spring is obtained by forcing an edge of the scraping element into contact with the belt surface, with a suitable degree of force. The pressurised contact surface between the belt and the scraping edge accelerates the wear rate of the tip of the scraping edge and can increase wear on the belt surface. It is also known that the pressure exerted by the scraping element on the belt surface must be increased, as belt speed increases, in order to provide the necessary cleaning resistance.
Protrusions on the belt surface cause the scraping element to deflect away from the belt whereafter the element rebounds naturally to its original position. This action can cause additional damage to the belt surface. In certain instances the rebound results in ongoing oscillations and vibrations of the scraping element and if this movement occurs in harmony with the natural vibration frequency of the conveyor belt severe belt damage can result, an effect which is compounded as the conveyor speed increases.
Also, unrestricted movement of the scraping element can cause additional damage when the belt reverses, and when used in the primary cleaning position if a belt joint/splice opens up, or other protrusions impact on the scraper.